Drum-brake with internal shoes



n. STEPHENS.

DRUM BRA-KE WITH INTERNAL SHOES. APPLICATION FILED JAN.23. I9I8.

1,327,068, I Patented J an. 6, 1920.

2 SHEETS-SHEET I.

R. STEPHENS,

Patented Jan.'6,1920{ Z SHEETS-SHEET 2- F a; 4- I 0mm BRAKE WITH INTERNAL sHoES.

' APPLICATION FILED JA&| 23r 1918- moi-ram) srnrnnns, or 'oLEvnnoiv, ENGLAND.

DRUM-BRAKE WITH INTERNAL SHOES.

' memes.

Specification of Letters Patent;

Patented Jan. 6, 1 920.

v Application filed January 23, 1918. Serial No. 213,294.

To all whomz't man concern:

Beit known that'I', RICHARD STEPHENS, of 9 The Triangle, Clevedon, Somerset, England,

a subject of the King of Great Britain and "Ireland, have invented certain new and useful Improvements in DrumBrakes with Internal Shoes, of which the following is a I specification.

. This invention relates to drum brakes of the kind in which braklng is efi'ected by I means of shoes which are contained within the drum andare adapted to be expanded or opened out, against the resistance of cou pling springs, to bear against the drum internally when operated for'braking,-and more especially to means for adjusting the.

shoes to compensate for wear thereof and of v the drum of the type in which the shoes are moved by wedge action effected throughthe medium of a screw device, without detach= ing the wheel or wheels fitted with the brakes- According to this invention the movement of the brake. shoes is effected by a wedgeshaped adjusting block disposed near the periphery of the brake shoes, and adapted to be moved transversely of the casingin which the brake shoes are disposed with means for limiting the movement of the brake shoes relatively to one another.-

Referring to the accompanying drawings, Figure 1 is an internal face view, with drum side cut-ofi, of a drum brake constructed in accordance with this invention. Fig. 2 is an edge view as seen looking in thedirection indicated by the arrow a, Fig. 1; The drum is shown as in part broken away. .Fig. 3 is a transverse sectional plan ,view on the line XX, Fig. 1. Fig. 1 is a rear view of a part of Fig. 3. Fig. 5 isa part face view of a construction in and relating to the adjust-' ment block. Figs. 6, 7, 8 and 9 show another construction. Fig. 9 is a sectional view, partly in elevation, of Fig. 8; Fig. 10

tened on two sides at the end at for a spanner to fit on, or for gripping by pincers, so that the pin 4 can thereby be turned. Instead of being thus'fiattened, the end part may be round throughout and have a cross groove or recess provided in it, like that in the pin head, to take the chisel end of a turn screw.

i In first assembling the parts, and before the shoes 2 and 3 are boxed in by the drum 12, the pin 1 is screwed in by means of a turn-screw, applied at the-pin head, until the head reaches the block 1 which stands at its maximum height in the gap between the shoes. Subsequent 'turnings of the pin 4 for adjustingthe shoes 2 and 3 are etlected from the other end 1 of the pin. The block 1 has tapered ends and has wings, fillets or ribs 6 which are also tapered and are of a partly rounded. conformation. has also fiat-faced flanks 7. The ends of the adapted to besli'd in the gap in which itcis placed between the said ends of the shoes.

The block 1 The pin 4, the underface of the head of" which bears on the block 1, is screwed into a fixed memberor part of the vehicle, engine, machlne or other appliance fitted with the brake. In the'accompanying drawings, the

said fixed part is the disk 8 of the axle casing. in a motor-car or like vehicle with which disk the axle casing is integral- The pin 4 is screwed into the disk 8 and into the boss-5 and is fitted with a nut 9-and lock nut' 9.

x As is usual in drum brakes which have internal shoes, the shoes are operated, in braking, by means of a cam l'Owhich is of the usual character and is actuated, as ordinari,ly,.by means of brake rods, levers and connected mechanism. Springs 11, whichare of the usual kind, and are expanded as the shoes are spread, return the shoes to the ofi' position when the cam for release of brake.

Vhen, owing to the wear of the linings or coatings 13 of the shoes 2 and 3 and of the internal face or" the flange of the drum 12, adjustments of the shoes are required to be made, in order to insure effective binding action of the brake, such adjustmentsare made without unfixing the drum 12. The nut 9 is first relaxed and, by means of a spanner or other instrument applied at the end 4* of the pin 4, projecting out beyond the axle casing 10 is turned and the other shoe in the opposite direction. whereby one end of each of the shoes would 10 would normally tend to cause one shoe to move bodily in one direction, as for instance, in the d1rection of the arrow 0 (Fig. 1),

be caused to partially bear-against the drum, thereby causing unevenness of wear. For

convenience in description, this movement of the shoes is herein termed traversing movement. One of the objects of this invention is to ermit the pivotal movement of the shoes a out an axis withoutpermitting such traversing movement, and this object is accomplished by all of the modified structures herein illustrated by reason of the fact that the wedge-shaped block 1, about which the shoes have a pivotal movement, isprevented-from following such pivotal move ment; in other words, 18 held against y1eld-'- ing to the pressure of the shoe 2 on. one side thereof and the pressure of the shoe 3 on the opposite side, which combined pressures, be-

normally tend to turn the block about its center as an axis.

' In the construction shown in Figs. 1 to 1 inclusive, the turning of the block is prevented by means of the arm'15, which is in tegral with the block 1 and extends between the flat web portions of the shoes 2 and3.

. In the construction shown in Fig. 5, the flat faced flanks 7 of the block 1 bearing against the correspondingly shaped faces 14 of the shoes are relied upon to. prevent such turnin of the block. v

In the construction shown in. Fig. 6, the block is prevented from turning by the arm mg exerted in opposite directions, would 15 which is integral with the block 1 and is restrained from sidewise movement by studs 16 fixed in the axle casing 8.

Thearm 15 is slidable toward and fromthe disk 8. In the construction shown in Fig. 7 the arm 15 of the block 1 is slidable upon but can not turn about the fixed stud 17. In Figs. 8 and 9 is shownanother construction for preventing traversing movement of the shoes.v In this arrangement the shoe 2 has a tongue 18 which is received into a channel 19 proyided at the back of the shoe 3 and bears at one side against a lug 20 which projects rearward from the shoe 3.

In the construction shown in Figs. 10 and 11, the adjusting block 1 does not lie directly on the shoes 2 and 3,-but lies between the outer parts of a pair of arms 21 which are pivotal about studs 22 fixed in the disk 8. In making adjustments of the shpes, the block 1 does not press the shoes against the disk 8. The overhanging parts 23 of the arms 21 keep the shoes from moving toward the drum side. a v

The said arms '21 which are loosely'held down by nuts, prevent traversing movement of the shoes.

According to another construction the means of adjusting may be a cone loosely carried on the pivot pin ,What I claim and desire to secure by Letv ters Patent is:

A brake comprising a drum, shoes within the drum, a wedge interposed between one of the ends of said shoes, and movable transverse ly thereof, wings formed on said wedge,

the aforementioned ends of saidshoes being pivotal about said wings, a radially dis posed arm integral with said wedge and interposed between the adjacent ends Of/Sfiid shoes, and means at the opposite ends of said shoes for forcing the same apart.

In testimony whereof I have signed hey i name.v to this specification.

' 'RIGHARD STEPHENS. 

